The oilfield was brought into production by the Iraq Petroleum Company (IPC) in 1934 when the 12-inch pipelines from Kirkuk (British-ruled Mandatory Iraq) to Haifa (Mandatory Palestine) and Tripoli (French-ruled Greater Lebanon) were completed.
Some analysts believe that poor reservoir-management practices during the Saddam Hussein years may have seriously, and even permanently, damaged Kirkuk's oilfield.
One example showed an estimated 1.5 billion barrels (240 million cubic metres) of excess fuel oil being reinjected.
[1] On 11 July 2014 Kurdistan Regional Government forces seized control of the Kirkuk oilfield, together with the Bai Hassan field, prompting a condemnation from Baghdad and a threat of "dire consequences," if the oilfields were not returned to Iraq's control.
[2] In the aftermath of the Kurdish Referendum, as part of 2017 Iraqi–Kurdish conflict, the control of the oil fields, along with almost all of Kirkuk Governorate, returned to the government of Iraq.